Gemstone



FIG. 1 is a top plan view of a gemstone showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a front plan view thereof;

FIG. 4 is a left side plan view thereof;

FIG. 5 is a right side plan view thereof; and,

FIG. 6 is a back side plan view thereof. 

I claim the ornamental design for a gemstone, as shown and described. 